8309902: C2: assert(false) failed: Bad graph detected in build_loop_l…

…ate after JDK-8305189

Reviewed-by: chagedorn
Backport-of: 26efff758684b9c5615fb3b087538d713e6eca10

src/hotspot/share/opto/loopTransform.cpp

@@ -2043,12 +2043,6 @@ bool IdealLoopTree::is_invariant(Node* n) const {
 // to the new stride.
 void PhaseIdealLoop::update_main_loop_assertion_predicates(Node* ctrl, CountedLoopNode* loop_head, Node* init,
                                                            const int stride_con) {
-  if (init->Opcode() == Op_CastII) {
-    // skip over the cast added by PhaseIdealLoop::cast_incr_before_loop() when pre/post/main loops are created because
-    // it can get in the way of type propagation
-    assert(((CastIINode*)init)->carry_dependency() && loop_head->skip_predicates() == init->in(0), "casted iv phi from pre loop expected");
-    init = init->in(1);
-  }
   Node* entry = ctrl;
   Node* prev_proj = ctrl;
   LoopNode* outer_loop_head = loop_head->skip_strip_mined();

test/hotspot/jtreg/compiler/loopopts/TestAssertPredicatePeeling.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2023, Red Hat, Inc. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8309902
+ * @summary C2: assert(false) failed: Bad graph detected in build_loop_late after JDK-8305189
+ * @run main/othervm  -Xcomp -XX:CompileCommand=compileonly,TestAssertPredicatePeeling::* TestAssertPredicatePeeling
+ */
+
+
+public class TestAssertPredicatePeeling {
+    static volatile long instanceCount;
+
+    public static void main(String[] strArr) {
+        test();
+    }
+
+    static int test() {
+        int i2 = 2, i17 = 3, i18 = 2, iArr[] = new int[10];
+
+        int i15 = 1;
+        while (i15 < 100000) {
+            for (int i16 = i15; i16 < 1; ++i16) {
+                try {
+                    iArr[i16] = 5 / iArr[6];
+                    i17 = iArr[5] / i2;
+                    i2 = i15;
+                } catch (ArithmeticException a_e) {
+                }
+                instanceCount -= i15;
+            }
+            i15++;
+        }
+        return i17;
+    }
+}
+